Thursday, June 30, 2011

Slant artists

UPDATE: Unfortunately, Todd Libhart died after a racing incident on October 12, 2014. He was competing at the 'Devil's Staircase' AMA event at Oregonia, OH. He was conscious after the crash, but died later in hospital. I originally wrote this account of Libhart and his Triumph-powered hill climb bikes in 2009.

The AMA sanctions a professional hillclimb championship. This is not a 'Pikes Peak' style hillclimb, it's a short, brutal drag race up an ungroomed mountainside so steep you can barely climb it on foot. 

The championship dates back to the Great Depression, when factory support for flat track racing nearly dried up, and promoters couldn't draw enough paying customers to justify renting tracks. Putting on a hillclimb was cheap. All you needed was a steep hill, and since the races only lasted a few seconds, wear and tear on equipment was minimal. During the sport's heyday (from 1930 until WWII) Harley-Davidson and Indian entered stars like Joe Petrali in events across the country. Nowadays, it's shrunk back to the point where, this year, five of nine events will be held in the Allegheny Mountains of western Pennsylvania.

Still, it's a national championship, and in 2008 I was surprised to see that a guy named Phil Libhart had won the title on a bike with a '70s Bonneville motor. Libhart's Triumph twin was racing against bikes powered by Yamaha R1 motors and GSX-R1000s. I figured he was a special kind of lunatic, and put him on my list of stories to track down.

Phil and his brother Todd ride for a team run by an old Pennsylvania hillclimber named Ralph Kreeger. Although it's staunch Harley country - there's a big assembly plant in nearby York, PA - Kreeger was always a Triumph man. Years ago, Ralph was a member of York's White Rose Motorcycle Club. He met a local hillclimber named Bees Wendt at the club, and Bees gave him an introduction to the world of 'slant artists.' Ralph took to it, fitting an extended swingarm to his Trackmaster Triumph. Later, he made his own frame, taking cues from the Trackmaster design, but leaving more room around the engine, so he could pull the heads without taking the motor out.

Todd Libhart, on the smaller of three Triumphs built to Ralph Kreeger's original pattern. Ralph wanted me to point out that Phil is the machinist wizard that keeps these bikes running.
Ralph finally hung up his helmet after one too many hard crashes. "I can handle broken arms and legs," he told me, "but when you start knocking your brain around, it's time to stop." He'd met Phil Libhart at a local flat track race, and he offered Phil a ride on his bike. Ralph passed along the knowledge that Bees Wendt had given to him, plus interest. They built a couple more frames, and the team currently has three bikes; Phil runs a stock-displacement Bonneville in the 'Extreme' class (basically anything displacing under 750cc) and a Bonnie punched-out to 788cc in the Unlimited class. His little brother Todd races the bike Ralph originally gave to Phil. It's got a 1970 Daytona engine bored to 540cc.

All the motors drink nitromethane from Hillborn fuel injectors. The bikes are fitted with Nourish cranks and eight-valve heads, Carillo rods, and CP pistons made to the team's own spec. Hillclimb bikes use only one speed, so they modify the gearboxes to run top gear only; that leaves empty space in the box, allowing it to double as an oil tank. Although it's hard to get reliable dyno figures using nitro, the little bike makes about 150 horsepower. Phil's bikes put out around 200.

The typical competition hill's only about 500 feet, and runs last from four to eight seconds. There's no practice; riders eyeball the hill and try to choose a line, then they make two timed runs. In the last few years, to control increasing speeds, organizers have started throwing in a couple of turns, but over the course of the championship, bikes are wide open for less than five minutes. I was surprised that a 40 year-old Bonneville motor could produce 200 horsepower even that long.

"There's about thirty hours of machining in each set of cases," Phil told me. "You'd be surprised how far out of parallel the axis of the cam and crank are. We get them all squared up; we fit steel inserts for the main bearings, and we cut improved oilways." Even at that, last year was the first time they got a whole season out of a set of cases. They've blown the cylinders off the top and cranks out the bottom.

"I think I'm driving the price of vintage Triumphs up around here," Phil laughed, "I buy so many old bikes just to get the cases."

Despite racing against modern motors, Phil's finished near the top of the standings in one or both of his classes for over ten years. According to Ralph, it's because their Triumph twins have a better punch right off the bottom.

"We gain an advantage in the first 100 feet," he told me, "before the four-cylinder bikes really make their power. Then, the question is, 'Can we hold on 'til the top?'"

Yeah, can they hold on, and will it hold together? I'm not sure I'd want to straddle one, myself, at least not without one of those Kevlar 'diapers' they wrap over drag race motors to catch shrapnel. But the old twins don't put Phil at much of a disadvantage, because hillclimb bikes are limited by traction, not power. The bikes have wheelbases of around 96", with nearly a foot of adjustment. The essential tuning skill is choosing the right wheelbase for conditions. If you go too long, it will just spin the rear tire. (Phil uses chains, but some competitors run paddle tires.) If you go too short, you'll get traction at the rear but the bike will loop out.

"If I get it just right," Phil said, "I can make the entire run without the front wheel ever touching the ground. When you wheelie a ten foot-long motorcycle, you're a long way up. It's not always the fastest way, but it's the most fun."

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